×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Wilson's Deposition Velocity

Wilson's Deposition Velocity

Wilson's Deposition Velocity

(OP)
One of the methods used to determine deposition/settling velocity in slurry pumping applications is to use Wilson's nomograph which relates deposition velocity to pipe diameter, "average" particle size (normally d50) and specific gravity of the solids being pumped. If anyone is familiar with this nomograph, they will no that the original equations describing the nomograph were converted into the nomograph at a time when personal computers were not so common. Can anyone assist in supplying the actual equations that were used to develop the nomograph so that I can incorporate these into a spreadsheet? This would remove the need to continually read off values from the nomograph manually.

Thanks in anticipation.

RE: Wilson's Deposition Velocity

In the book Slurry Transport Using Centrifugal Pumps co-authored by Wilson, Addie and Clift, the following formula is given:

(Vsm)max/(2gD(Ss-Sf)^1/2=(0.018/f)^0.13

f is friction factor for fluid alone. V. Matousek recommends f=0.55 for most solids.

This formula does not give exactly the same results as you get from the nomograph since the formula was developed later.

The formula and the nomograph do not include the effect of slurry concentration. Wilson has given the method for the correction based on concentration. This method is a bit too much for writing out here.

RE: Wilson's Deposition Velocity

Continue the above post.

This formula (Vsm)max/(2gD(Ss-Sf))^1/2=(0.018/f)^0.13 is just for large pipe, and particles near Murphian size, he regards the particle size does not influence the Vsm.

In 1992 Wilson proposed another formula which is not included in the 1992 version of the book Slurry Transport Using Centrifugal Pumps:

Vsm=8.8*(f*(Ss-Sf)/0.66)^0.55*D^0.7*d50^1.75/(d50^2+0.11*D^0.7)

Again, f is the friction factor between solids and pipe wall.
d50 is the average particle size, D is the pipe ID.
Ss and Sf are SG of solids and fluid respectively.

This formula still does nopt give the same result as the nomograph and I've not heard the comparison by the author yet (I do not have the newer version of the book than 1992)

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources